1. Field of the Invention
This invention relates to a remote control positioning system, and more particularly, to a remote control system provided with a hydraulic drive system for positioning the ballast gate doors on a railroad hopper car, and with a radio frequency control system for remote operation.
The present invention utilizes the pneumatic power supply furnished by the locomotive to the railroad hopper cars. The pneumatic power is converted to hydraulic power to drive the hopper doors when opening and closing the doors to selectively discharge ballast material. The radio frequency transmitter and receiver included as part of the system provide an accurate and economical means for achieving remote operating capabilities.
The principal application for the present system is the remote control operation of ballast door mechanisms on railroad hopper cars, which facilitates selective discharge of stone ballast from the railroad hopper cars onto the road bed of a railway. The control system of the present invention may also be used in other hydraulic drive and positioning applications where the available power is a pneumatic power supply, such as large trucks and other similar applications.
2. Description of the Prior Art
A remote control feature is desired in many drive system applications where no source of electrical power is readily available. A railway freight car has a source of compressed air available, i.e. the locomotive air supply, but no source of electrical power. The railway ballast car is a hopper-type railway car where the remote control operation of the hopper gates/doors provides many safety and efficiency benefits.
The need for reballasting of railway road beds results from the loading and unloading of sections of track caused by the passage of wheels of railroad cars traveling on the track. The resultant flexing action of the track tends to force the ballast stone out from under the associated ties. The phenomenon is especially pronounced at the end of the ties, with the result that more ballast is pushed out from under the ties outside the rails than inside the rails. For safe railroad operation, it is necessary to replace the lost ballast. In the early days of the railroad, lost ballast was replenished manually.
When manual reballasting of the road bed was no longer economically feasible, specialized railway cars were developed. These specialized railway cars were provided with hopper doors capable of directing the flow of ballast to the various sections of road bed, including the area between the parallel spaced apart rails, and the area outside the rails. The first of these discharge arrangements were operated manually, such as disclosed in the U.S. Pat. No. 4,452,149 to LeMarbe, and U.S. Pat. No. 4,454,822 to Fischer. While these ballast cars satisfactorily directed the flow of ballast to the various sections of the road bed, the operator was required to walk along side the car as the ballast car moved along the rails. Safety problems arose because of the operator's close proximity, not only to the moving railway car, but to the heavy stone as it was discharged onto the road bed.
These safety problems led to the hydraulic operation of railway ballast cars. The car operator could operate a hydraulic actuated lever some distance away from the discharge area of the ballast gates, and thereby eliminate many of the aforementioned safety problems. An example of such hydraulically operated ballast gates is illustrated in U.S. Pat. No. 5,163,372 to Galvan et al.
An improved hydraulically operated railway ballast car is disclosed in commonly assigned U.S. Pat. application Ser. No. 07/887,358, filed May 21, 1992 now U.S. Pat. No. 5,261,333, in the name of Daniel L. Miller and is specifically incorporated herein by reference. The application discloses the use of an air-operated hydraulic pump, which utilizes the available pneumatic power supply furnished by the locomotive to the hopper car, to power hydraulic cylinders to operate the ballast gate doors. While the use of an air-operated hydraulic pump to supply the hydraulic pressure is an improvement, the operator's presence is still required in close proximity to a moving train. The operator is still endangered both by the moving train and by the ballast as it is discharged from the hopper car.
Thus, those skilled in the art of railway ballast cars continued to search for a solution to the safety problems presented in the use of such cars. The present invention eliminates certain safety problems noted in the prior art by permitting the operator to accurately control the opening and closing of the hopper doors from a distance. The present invention provides a ballast gate positioning system having radio frequency remote operation with means for converting the pneumatic power supply, which is supplied to the hopper car by the locomotive, to electrical power for control operations and to hydraulic power for ballast gate positioning operations.